Transcript Parameter name Description Value Comments regarding choice of

Team 3 ATV
Daniel Barrett
Sebastian Hening
Sandunmalee Abeyratne
Anthony Myers
 High Criticality
 A failure that has the potential to injure the user or
others
 Medium Criticality
 A failure that can permanently damage components of
the device
 Low Criticality
 A failure that would change the functionality of the
device or affect its performance
Devices prone to fail
 Freescale 9S12C32 microcontrollers
 Murata OKR-T 5V switching regulator
 BQ2002 Batter charging IC
 L298 dual H-Bridge
μController 1
Failure No.
Failure Mode
A1
PWM signal
failure
A2
SCI failure
A3
Failure of range
sensors
A4
Failure to Reset
or run
A5
A6
Possible Causes
Failure Effects
Method of
Detection
Criticality
Failure of
The camera servos will not work.
HC9S12C32 pins
PT0-PT3.
Failure of the
Unable to communicate to atom
HC9S12C32 pins board.
TX and RX.
Observation
Medium
Observation
Medium
Failure of the
HC9S12C32
ATD pins AN3AN5
Failure of R9 or
Pushbutton
Unable detect obstacles. Can
result in injury of others.
Observation
High
The microcontroller is unable to
reset or is being constantly reset
Observation
Medium
Failure of SPI
Failure of
HC9S12C32 SPI
pins PM2-PM5
Unable to read the accelerometer
data. Will make the calculation of
the current location less accurate
Observation
Low
Failure of Timer
Failure of
HC9S12C32
timer pins PT6PT7
Unable to determine the speed
and direction of the robot
Observation
Medium
Re
ma
rks
μController 2
Failure No.
Failure Mode
Possible Causes
Failure Effects
Method of
Detection
Observation
Criticality
High
B1
Failure of Motor
logic signals
Failure of the
HC9S12C32
AN0-AN3 pins
Unable to control
the movement of
the robot.
B2
SCI failure
Failure of the
HC9S12C32 pins
TX and RX.
Unable to
communicate to
atom board.
Observation
Medium
B3
SPI Failure
Failure of the
HC9S12C32 pins
PM2-PM5 or
failure of
Compass
Unable to
determine the
direction of
movement of the
robot
Observation
Low
B4
Failure to Reset
Failure of R9 or
Pushbutton
The
Observation
microcontroller is
unable to reset or
is being
constantly reset
Medium
B5
Failure of PWM
signal
Failure of the
HC9S12C32 pins
PT0-PT1
The motors are
not able to stop
High
Observation
Remarks
μController
Parameter name
Description
Value
Comments regarding
choice of parameter
value, especially if you
had to make
assumptions.
CMOS, 8-Bit
C1
Die complexity
.14
πT
Temperature coeff.
.71
C2
Package Failure Rate
.015
Assume linear temp of
50 C
32 Pins, Nonhermetic
πE
Environmental Factor
4.0
Ground Mobile
πQ
Quality Factor
10
πL
Learning Factor
1
λP
Part Failure Rate
1.594
Commercially
Manufactured
component
More than 2 years in
production
Failures /10^6 hours
MTTF
627352 Hours = 71.5 Years
Murata OKR-T 5V Regulator
Failure No.
Failure Mode
Possible Causes
Failure Effects
D1
Vout < 5V
R15 fails and
causes an open
circuit
D2
Vout >5V
R15 fails and
shorts
D3
Vout <5 or Vout
>5V
Failure of OKRT switching
regulator
The servos,
sensors and
microcontrollers
do not function
The sensors and
microcontroller
might be
damaged
Unpredictable
Method of
Detection
Observation
Criticality
Observation
Medium
Observation
Medium
Medium
Remarks
Murata OKR-T
Parameter name
Description
Value
Comments regarding choice
of parameter value, especially
if you had to make
assumptions.
C1
Die complexity
.01
1 to 100 Linear MOS gates
πT
Temperature coeff.
.71
Assume linear temp 50 C
C2
Package Failure Rate
.002
5 Pins, Nonhermetic
πE
Environmental Factor
4.0
Ground Mobile
πQ
Quality Factor
10
πL
Learning Factor
1
λP
Part Failure Rate
.207
Commercially Manufactured
component
More than 2 years in
production
Failures /10^6 hours
MTTF
551 Years
H-Bridge
Failure No.
Failure Mode
Possible Causes
Failure Effects
E1
Unable to
control motors
Motor behave
randomly and
cannot be
controlled
E2
H-bridge failure
One of the
Resistors R21R26 fails or one
of the six 4n33
optical isolators
fails
Failure of the
L298 H-bridge
Unpredictable,
motors cannot
be controlled
and robot might
run into
someone
resulting in
injury
Method of
Detection
Observation
Criticality
Observation
High
High
Remarks
L298 dual H-Bridge
Parameter name
Description
Value
C1
Die complexity
.01
Comments regarding choice
of parameter value, especially
if you had to make
assumptions.
1 to 100 Linear MOS gates
πT
Temperature coeff.
2.8
Linear MOS at 70C
C2
Package Failure Rate
.0067
15 Pins, Nonhermetic
πE
Environmental Factor
4.0
Ground Mobile
πQ
Quality Factor
10
πL
Learning Factor
1
λP
Part Failure Rate
.548
Commercially Manufactured
component
More than 2 years in
production
Failures /10^6 hours
MTTF
208.4 Years
Battery Charging Circuit
Failure No.
Failure Mode
Possible Causes
Failure Effects
F1
Current source
failure
Failure of
charging IC
LM-317 failure
F3
Failure of Q1
Failure of the
Q1 transistor
F4
Failure of Q2
Transistor Q2
fails
F5
Current soure >
1A
Current soure
<1A
Resistors R5 or
R6 fail.
Resistor R5 or
R6 failure
The battery does not
charge
Failure to detect when
battery is charged
which can lead to
destruction of battery.
Batter can also
explode.
Unpredictable. Unable
to start charging or
stop charging the
battery. Battery can
explode or ignite.
This is in place only in
case other components
fail. Its failure might in
the worst case make
the battery unable to be
charged.
LM317 current source
breaks
The battery doesn’t
fully charge
F2
F6
Failure of
BQ2002/F chip
Method of
Detection
Observation
Criticality
Observation
High
Observation
High
Observation
Low
Observation
Low
Observation
Low
Low
Remarks
BQ2002
Parameter name
Description
Value
C1
Die complexity
.02
Comments regarding choice
of parameter value, especially
if you had to make
assumptions.
101 to 1000 Linear MOS gates
πT
Temperature coeff.
.71
Assume linear temp of 50 C
C2
Package Failure Rate
.0034
8 Pins, Nonhermetic
πE
Environmental Factor
4.0
Ground Mobile
πQ
Quality Factor
10
πL
Learning Factor
1
λP
Part Failure Rate
.278
Commercially Manufactured
component
More than 2 years in
production
Failures /10^6 hours
MTTF
410 Years
Questions?